As a plasma processing apparatus for manufacturing a semiconductor device, a plasma chemical vapor deposition (CVD) apparatus which includes an introduction system and an exhaust system for gas provided in a reaction chamber, and generates plasma in the reaction chamber using a process gas and a high-frequency power, to form a thin film on a substrate by, and a dry etching apparatus which performs etching in a desired shape, and the like has been known in the art.
The plasma processing apparatus includes the reaction chamber for forming a film on the substrate and performing etching processing, a gas introduction unit for introducing a mixture of a plurality of gases including the process gas or the process gas alone into the reaction chamber, an exhaust unit for exhausting the process gas introduced into the reaction chamber, a pressure control valve for controlling exhaust velocity of the process gas to keep a predetermined pressure value in the reaction chamber, and the like, and controls an opening degree of the pressure control valve by a pressure controller depending on a detection signal of a vacuum gauge provided in the reaction chamber, thereby controlling the pressure in the reaction chamber. After controlling the pressure, in a semiconductor manufacturing apparatus in which a high-frequency power supply is provided, a high-frequency power is applied to an upper electrode and a lower electrode, such that plasma is generated in the reaction chamber, and processing is performed on the substrate which is mounted on the lower electrode using the generated plasma.
In the plasma processing apparatus, a product generated in the reaction chamber during the film forming processing and an etching product generated during the etching processing are deposited in the reaction chamber. The deposits not only generate particles in the reaction chamber, but also change a capacity of the reaction chamber. In addition, partial pressure of the process gas is changed due to outgas and the like from the deposits adhered inside the reaction chamber, such that processing characteristics of the process are also changed. Therefore, there is a need to regularly remove the product deposited in the reaction chamber depending on a processing amount or operation time.